U.S. patent number 8,191,794 [Application Number 12/308,072] was granted by the patent office on 2012-06-05 for flow channel switching device.
This patent grant is currently assigned to Toyota Jidosha Kabushiki Kaisha. Invention is credited to Akiharu Abe, Manabu Hasegawa, Kazumichi Sasaki.
United States Patent |
8,191,794 |
Sasaki , et al. |
June 5, 2012 |
Flow channel switching device
Abstract
A flow channel switching device provided in an oil circuit to
switch the oil flow channel in accordance with the temperature of
the oil. The flow channel switching device includes: a thermo-valve
case that includes a plurality of flow passages that are
communicated outside of the case; and a cylinder that is formed to
move in the thermo-valve case and switches the oil flow channel in
accordance with the temperature of the oil. The cylinder moves to a
predetermined position and is fixed by means of an external member
when the fluid at a low temperature is fed into the fluid
circuit.
Inventors: |
Sasaki; Kazumichi (Toyota,
JP), Abe; Akiharu (Toyota, JP), Hasegawa;
Manabu (Kariya, JP) |
Assignee: |
Toyota Jidosha Kabushiki Kaisha
(Toyota, JP)
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Family
ID: |
38734925 |
Appl.
No.: |
12/308,072 |
Filed: |
June 13, 2007 |
PCT
Filed: |
June 13, 2007 |
PCT No.: |
PCT/IB2007/001575 |
371(c)(1),(2),(4) Date: |
January 12, 2009 |
PCT
Pub. No.: |
WO2007/144746 |
PCT
Pub. Date: |
December 21, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20090272441 A1 |
Nov 5, 2009 |
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Foreign Application Priority Data
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Jun 14, 2006 [JP] |
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2006-165005 |
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Current U.S.
Class: |
236/99K; 137/468;
236/100; 236/99R; 236/99J; 236/93A; 236/93R |
Current CPC
Class: |
F01P
11/02 (20130101); F16H 57/0413 (20130101); F01P
7/16 (20130101); Y10T 137/7737 (20150401) |
Current International
Class: |
G05D
23/02 (20060101); G05D 23/275 (20060101); G05D
23/12 (20060101) |
Field of
Search: |
;236/93A,93R,99J,99K,99R,100 ;137/468 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1743706 |
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Mar 2006 |
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CN |
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0 214 938 |
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Mar 1987 |
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EP |
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0 890 717 |
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Jan 1999 |
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EP |
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Y-45-31995 |
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Dec 1970 |
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JP |
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U-51-37319 |
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Mar 1976 |
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JP |
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A-61-4816 |
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Jan 1986 |
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JP |
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U-63-82029 |
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May 1988 |
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JP |
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A-64-15587 |
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Jan 1989 |
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JP |
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U-1-98365 |
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Jun 1989 |
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JP |
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A-1-275982 |
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Nov 1989 |
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JP |
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A-6-17633 |
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Jan 1994 |
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JP |
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U-6-16788 |
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Mar 1994 |
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JP |
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A-10-196841 |
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Jul 1998 |
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JP |
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A-2006-64155 |
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Mar 2006 |
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JP |
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WO 2005/103508 |
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Nov 2005 |
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WO |
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Other References
Japanese Decision of Refusal issued in Japanese Application No.
2008-254370 on Mar. 8, 2011. cited by other .
Japanese Office Action issued in Japanese Patent Application No.
2006-165005 on Apr. 22, 2008. cited by other .
Japanese Office Action issued in Japanese Patent Application No.
2008-254370 (divisional of Japanese Patent Application No.
2006-165005) on Oct. 14, 2010. cited by other .
Chinese Office Action issued in Chinese Patent Application No. CN
200780022334.7 dated Jun. 21, 2010. cited by other.
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Primary Examiner: Tyler; Cheryl J
Assistant Examiner: Bradford; Jonathan
Attorney, Agent or Firm: Oliff & Berridge PLC
Claims
The invention claimed is:
1. A flow channel switching device comprising: a case that includes
a plurality of flow passages that are communicated outside of the
case, and a valve body that is formed to move in the case, and
switches the flow channel of the fluid in accordance with a
temperature of the fluid, wherein the valve body is movable to a
predetermined position and is fixable by an external member when
the fluid at a low temperature is fed into a fluid circuit, and
wherein the plurality of flow passages includes a first input
passage to the valve body that is open when the temperature of the
fluid is low; and a second input passage to the valve body that is
open when the temperature of the fluid is high, and a predetermined
position is a position in which the valve body is seated when the
first input passage is blocked, a shaft that supports the valve
body such that the valve body moves in a predetermined direction;
and a wax that is provided in a space enclosed by the valve body
and the shaft, the wax expands and contracts in accordance with the
temperature of the fluid, wherein the valve body is moved in the
predetermined direction by the wax expanding, a portion of the
shaft is inserted in the valve body while another portion of the
shaft is exposed to the outside of the case, and the shaft is
supported by the case to move in the predetermined direction, when
the fluid is fed into the fluid circuit, the valve body is moved in
the predetermined direction by pushing the shaft inward, whereby
the first input passage is blocked and the second input passage is
opened, wherein the shaft is fixed by the external member in a
state that the shaft is pushed in the predetermined direction, and
the flow channel switching device further comprises a biasing
member that biases the valve body in a direction opposite to
pushing the shaft inward, and wherein the external member is a pin
having an elongated shape, the case has an insert hole into which
the pin is inserted, and the pin is inserted into the insert hole
in a state that the shaft is pushed inward, whereby an end face of
the shaft contacts with the inserted pin, and the shaft is
fixed.
2. The flow channel switching device according to claim 1, wherein
the external member is removable.
3. The flow channel switching device according to claim 1, wherein
the fluid circuit is a hydraulic circuit for an automatic
transmission.
4. The flow channel switching device according to claim 1, wherein
the fluid circuit is a coolant circuit for an internal combustion
engine.
5. The flow channel switching device according to claim 1, wherein
the valve body includes a first closing portion that blocks the
first input passage; and a second closing portion that blocks the
second input passage, and the second closing portion is forced to
move when a fluid is fed into the fluid circuit, and the second
input passage opens.
6. The flow channel switching device according to claim 1, wherein
the case further includes a protruding portion that has a plurality
of insert holes extending in different directions from adjacent
insert holes.
7. A flow channel switching device comprising: a case that includes
a plurality of flow passages that are communicated outside of the
case; and a valve body that is formed to move in the case, and
switches the flow channel of the fluid in accordance with a
temperature of the fluid, wherein the valve body is movable to a
predetermined position and is fixable by an external member when
the fluid at a low temperature is fed into a fluid circuit, and
wherein the plurality of flow passages includes a first input
passage to the valve body that is open when the temperature of the
fluid is low; and a second input passage to the valve body that is
open when the temperature of the fluid is high, and a predetermined
position is a position in which the valve body is seated when the
first input passage is blocked, a shaft that supports the valve
body such that the valve body moves in a predetermined direction;
and a wax that is provided in a space enclosed by the valve body
and the shaft, the wax expands and contracts in accordance with the
temperature of the fluid, wherein the valve body is moved in the
predetermined direction by the wax expanding, a portion of the
shaft is inserted in the valve body while another portion of the
shaft is exposed to the outside of the case, and the shaft is
supported by the case to move in the predetermined direction, when
the fluid is fed into the fluid circuit, the valve body is moved in
the predetermined direction by pushing the shaft inward, whereby
the first input passage is blocked and the second input passage is
opened, and wherein the case has a concave portion that is formed
to expose the other portion of the shaft to the outside of the
case, the external member is a screw member, the screw member is
screwed into the concave portion, and the shaft is pushed in the
predetermined direction by screwing the screw member into the
concave portion when the fluid is fed into the fluid circuit.
8. The flow channel switching device according to claim 7, wherein
the external member is removable.
9. The flow channel switching device according to claim 7, wherein
the fluid circuit is a hydraulic circuit for an automatic
transmission.
10. The flow channel switching device according to claim 7, wherein
the fluid circuit is a coolant circuit for an internal combustion
engine.
11. The flow channel switching device according to claim 7, wherein
the valve body includes a first closing portion that blocks the
first input passage; and a second closing portion that blocks the
second input passage, and the second closing portion is forced to
move when a fluid is fed into the fluid circuit, and the second
input passage opens.
12. The flow channel switching device according to claim 7, wherein
the shaft is fixed by the external member in a state that the shaft
is pushed in the predetermined direction.
13. A method of filling a fluid circuit with oil, wherein a
thermo-valve is provided in the fluid circuit and switches a flow
channel in accordance with a temperature of the oil, the
thermo-valve includes a case that includes a plurality of flow
passages that are communicated outside of the case, and a valve
body that is formed to move in the case, and switches the flow
channel in accordance with the temperature of the oil; when the
temperature of the oil is low, the valve body is moved to a
position at which the valve body is located when the temperature of
the oil is high, and is fixed from outside of the case at the
position; the fluid circuit includes a first oil circuit and a
second oil circuit; when the temperature of the oil is low, the oil
flows to the first oil circuit; when the temperature of the oil is
high, the oil flows to the second oil circuit; a first heat
exchanger, a second heat exchanger, and a passage that connects the
first heat exchanger to the second heat exchanger are filled with
the oil, when the temperature of the oil is low and the valve body
is fixed from outside of the case at the position at which the
valve body is located when the temperature of the oil is high; the
method includes: when the temperature of the oil is low, filling a
low temperature-side passage with the oil; and when the temperature
of the oil is low, filling a high temperature-side passage with the
oil by fixing from outside of the case the valve body at the
position at which the valve body is located when the temperature of
the oil is high; the thermo-valve includes a shaft that supports
the valve body such that the valve body moves in one direction, and
a wax that is provided in the valve body, and expands and contracts
in accordance with the temperature of the oil; a portion of the
shaft is inserted in the valve body; the wax is provided in a space
enclosed by the valve body and the shaft; when a temperature of the
wax increases and the wax expands, the valve body moves in the one
direction so that one of the plurality of flow passages is opened
and a rest of the flow passages is blocked; the shaft is supported
by the case to move in the one direction; a portion of the shaft is
exposed to the outside of the case; when the shaft is pushed
inward, the valve body moves in the one direction so that the one
of the plurality of flow passages is opened and the rest of the
flow passages is blocked; the shaft is fixed at a position to which
the shaft has been pushed inward in the one direction; and the
valve body is fixed by a removable member.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a flow channel switching device that
switches the flow channel of a fluid according to the temperature
of the fluid.
2. Description of the Related Art
A valve for switching a flow channel is provided in a fluid
circuit. Among various valves, a so-called thermo-valve that
switches the flow channel according to the temperature of the fluid
is typically used at a point at which two or more passages
intersect. A thermo-valve switches a flow channel from one to the
other according to the temperature of the fluid flowing through the
thermo-valve. A thermo-valve is provided for, for example, a heat
exchanger for an automatic transmission in a motor vehicle.
Japanese Utility Model Application Publication No. 1-98365
(hereinafter referred to as "JP-U-1-98365") describes a
transmission oil cooling apparatus that suppresses an increase in
the temperature of the transmission oil by circulating the
transmission oil through an oil pump, a circulation passage and an
oil cooler that is provided in the circulation passage. The
transmission oil cooling apparatus has a bypass passage bypassing
the oil cooler. An automatic switching valve is provided at the
connection portion between the bypass passage and the circulation
passage. When the oil temperature is low, the automatic switching
valve introduces the oil discharged from the oil pump to the bypass
passage while preventing the oil from flowing into the oil cooler.
When the oil temperature is high, the automatic switching valve
introduces the oil discharged from the oil pump to the oil cooler
while preventing the oil from flowing into the bypass passage.
According to JP-U-1-98365, it is described that the transmission
oil cooling apparatus can maintain the oil temperature within a
desired temperature range, and can quickly increase the oil
temperature when the oil temperature is low.
Meanwhile, Japanese Patent Application Publication No. 2006-64155
(hereinafter, referred to as "JP-A-2006-64155") describes a heat
exchanging system for an automatic transmission. The heat
exchanging system is configured to cool the automatic transmission
and the oil discharged from the automatic transmission. The heat
exchanging system includes a first heat exchanger provided on the
upstream side, a second heat exchanger provided the downstream
side, a thermo-valve that can supply the automatic transmission
with at least one of the oil that underwent the heat exchange at
the first heat exchanger and the oil that underwent the heat
exchange at the second heat exchanger. According to the heat
exchanging system, when the oil temperature is relatively low, the
thermo-valve establishes a flow channel in which the oil passed
through the first heat exchanger returns to the automatic
transmission while the oil passed through the second heat exchanger
is interrupted to return to the automatic transmission. Conversely,
when the oil temperature is relatively high, the thermo-valve
establishes a flow channel in which the oil passes through both the
first and second heat exchangers and then returns to the automatic
transmission. According to JP-A-2006-64155, it is described that
the heat exchanging system can stabilize the oil temperature.
Meanwhile, a thermo-valve is structured to switch a flow channel
between a circuit communicated when the fluid temperature is low
and a circuit communicated when the fluid temperature is high. When
forming a fluid circuit during production, pipes and valves are
first assembled together to form passages of the fluid circuit, and
then the fluid circuit is filled up. However, when the fluid
circuit is filled externally with the fluid at a low temperature,
for example, the thermo-valve may prevent the fluid from flowing
into the fluid circuit that is communicated at a high
temperature.
For example, at a room temperature, the passages that circulates
the fluid at a low temperature are open while the passages that
circulates the fluid at a high temperature are closed. Therefore,
when the fluid circuit is filled externally with the fluid at a
room temperature, the fluid is prevented from flowing into the
passages that are opened at a high temperature. That is, it is
difficult to fill up completely the passages that are opened only
at a high temperature with the fluid at a low temperature.
Therefore, for example, both the circuit that is opened at a low
temperature and the circuit that is opened at a high temperature
may be filled up in such a manner that after filling a portion of
the fluid circuit with the fluid at a low temperature, the other
portion of the fluid circuit is filled up externally with the fluid
heated up to a high temperature. According to this manner, however,
it takes excessively a long time to fill up the fluid circuit
completely because the fluid needs to be heated.
Also, the thermo-valve may be configured to be controlled
electrically such that a valve body of the thermo-valve moves from
a position for low temperature to a position for high temperature
even if the fluid is still at a low temperature. In this case,
however, the structure of the thermo-valve becomes complicated and
the cost of the thermo-valve increases.
SUMMARY OF THE INVENTION
The invention provides a flow channel switching device that even
though the temperature of a fluid is low, the fluid may be fed into
a fluid circuit that is communicated when the temperature of the
fluid is high.
An aspect of the invention relates to a flow channel switching
device that is provided in a fluid circuit and switches a flow
channel of a fluid in accordance with the temperature of the fluid.
The flow channel switching device comprises: a case that includes a
plurality of flow passages that is communicated outside; and a
valve body that is formed to move in the case, and switches the
flow channel of the fluid in accordance with the temperature of the
fluid. Specifically, the valve body moves to a predetermined
position and is fixed by means of an external member when the fluid
at a low temperature is fed into the fluid circuit.
Here, the external member may be removable. The flow passages may
include a first input passage that is open when the temperature of
the fluid is low, and a second input passage that is open when the
temperature of the fluid is high. The predetermined position may be
a position where the valve body is seated when the first input
passage is blocked.
Further, the fluid circuit may be a hydraulic circuit for an
automatic transmission, or may be a coolant circuit for an internal
combustion engine. Also, the valve body may include first closing
means for blocking the first input passage, and second closing
means for blocking the second input passage. The second closing
means may be forced to move when a fluid is fed into the fluid
circuit, and the second input passage opens.
The flow channel switching device descried above may further
include: a shaft that supports the valve body such that the valve
body moves in a predetermined direction; and a wax that is provided
in a space surrounded by the valve body and the shaft, the wax
expands and contracts in accordance with the temperature of the
fluid. The valve body may be moved in the predetermined direction
by the wax expanding. A portion of the shaft may be inserted in the
valve body while the other portion of the shaft is exposed to the
outside of the case. The shaft may be supported by the case to move
in the predetermined direction. When the fluid is fed into the
fluid circuit, the valve body may be moved in the predetermined
direction by pushing the shaft inward, whereby the first input
passage is blocked and the second input passage is opened.
The shaft may be fixed by the external member in a state that the
shaft is pushed in the predetermined direction.
Further, the flow channel switching device descried above may
further include an biasing member that biases the valve body in a
direction opposite to pushing the shaft inward. The external member
may be a pin having an elongated shape. The case may have an insert
hole into which the pin is inserted. The pin may be inserted into
the insert hole in a state that the shaft is pushed inward, whereby
an end face of the shaft contacts with the inserted pin and the
shaft is fixed. Also, the case may further include a protruding
portion that has a plurality of the insert holes extending in
different directions from the adjacent insert holes.
The case may have a concave portion that is formed to expose the
other portion of the shaft to the outside of the case. The external
member also may be a screw member. The screw member may be screwed
into the concave portion. The shaft may be pushed in the
predetermined direction by screwing the screw member into the
concave portion when the fluid is fed into the hydraulic
circuit.
According to the invention, even though the temperature of a fluid
is low, the fluid may be fed into a fluid circuit that is
communicated only when the temperature of the fluid is high.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and further objects, features and advantages of the
invention will become apparent from the following description of
example embodiments with reference to the accompanying drawings,
wherein like numerals are used to represent like elements and
wherein:
FIG. 1 is a cross-sectional view showing a flow channel switching
device of the first example embodiment when the temperature of the
oil in the hydraulic circuit is low;
FIG. 2 is a side view showing the flow channel switching device of
the first example embodiment as viewed from the direction indicated
by the arrow X in FIG. 1;
FIG. 3 is a block diagram showing a drive system in the first
example embodiment when the temperature of the oil in the hydraulic
circuit is low;
FIG. 4 is a cross-sectional view showing the flow channel switching
device of the first example embodiment when the temperature of the
oil in the hydraulic circuit is high;
FIG. 5 is a block diagram showing the drive system in the first
example embodiment when the temperature of the oil in the hydraulic
circuit is high;
FIG. 6 is a cross-sectional view showing the flow channel switching
device of the first example embodiment when the hydraulic circuit
is filled up with the oil;
FIG. 7 is a side view of the flow channel switching device of the
first example embodiment as viewed from the direction indicated by
the arrow 106 in FIG. 6;
FIG. 8 is a cross-sectional view showing a flow channel switching
device of the second example embodiment when the temperature of the
oil in hydraulic circuit is low;
FIG. 9 is a side view of the flow channel switching device of the
second example embodiment as viewed from the direction indicated by
the arrow 108 in FIG. 8;
FIG. 10 is a cross-sectional view showing the flow channel
switching device of the second example embodiment when the
temperature of the oil in hydraulic circuit is high; and
FIG. 11 is a cross-sectional view showing the flow channel
switching device of the second example embodiment when the
hydraulic circuit is filled up with the oil.
DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS
Hereinafter, a flow channel switching device (will be simply
referred to as "thermo-valve") according to the first example
embodiment of the invention will be described with reference to
FIG. 1 to FIG. 7. The thermo-valve 30 of the first example
embodiment is provided in a hydraulic circuit for an automatic
transmission in a motor vehicle. The hydraulic circuit of the first
example embodiment involves heat exchangers.
FIG. 1 is a cross-sectional view showing the thermo-valve 30 when
the temperature of the oil in the hydraulic circuit (hereinafter
referred to as "hydraulic oil") is low. The thermo-valve 30 has a
thermo-valve case 31 and a lid body 33. An inner space 32 of the
thermo-valve case 31 is formed hallow and serves as an oil passage.
The lid body 33 is arranged to seal one side of the inner space 32
such that the inner space 32 is separated from the outside.
The thermo-valve case 31 has, as flow passages communicated
outside, a second input port 142, a first input port 144, and a
first output port 143. The second input port 142, the first input
port 144, and the first output port 143 are formed to communicate
with the inner space 32, and the oil is delivered to and from other
components in the hydraulic circuit through the second input port
142, the first input port 144, and the first output port 143.
Further, the thermo-valve case 31 has a second output port 146 that
communicates with a second heat exchanger 50. As will be described
later, the second output port 146 is formed such that the hydraulic
oil flowing into the second output port 146 from a first heat
exchanger 40 flows toward the second heat exchanger 50 without
passing through the inner space 32 in the thermo-valve 30.
In the first example embodiment, the thermo-valve 30 has a cylinder
36 that serves as a valve body. The cylinder 36 has a hollow
inside. The cylinder 36 is arranged in the inner space 32 of the
thermo-valve case 31.
The cylinder 36 has a shaft slide portion 36a. The shaft slide
portion 36a is cylindrical. The shaft slide portion 36a is slidably
supported on a shaft 121 that is provided in the thermo-valve
30.
The shaft 121 includes a thermo-element shaft 34. The shaft slide
portion 36a is slidably supported on the thermo-element shaft 34.
The cylinder 36 is movable along the direction indicated by the
arrow 111. At least a portion of the thermo-element shaft 34 may be
inserted in the cylinder 36. The inside of the cylinder 36 is
filled with a wax 131. The wax 131 is hermetically sealed in the
space surrounded by the shaft 121 and the cylinder 36.
A gasket 35 is attached via a back-up plate 43 to an end portion of
the thermo-element shaft 34, which is closer to the inside of the
cylinder 36. The gasket 35 is formed such that the wax 131 in the
cylinder 36 is prevented from leaking out.
The wax 131 may be, for example, a paraffin wax. The wax 131
contracts as its temperature decreases and expands as its
temperature increases. Specifically, the wax 131 of the first
example embodiment is solid when the temperature of the hydraulic
oil is low and liquefies as the temperature of the hydraulic oil
increases. That is, the wax 131 may be regarded as a substance that
changes its volume according to its temperature.
The thermo-valve 30 has a passage closing member 135, which
corresponds to "first closing means". The passage closing member
135 closes the first input port 144 by contacting the opening
portion of the first input port 144. The cylinder 36 has a closing
member slide portion 36c that faces the first input port 144. The
closing member slide portion 36c protrudes from the front-end
portion of the cylinder 36. A stopper 91 is provided at the
front-end portion of the closing member slide portion 36c. The
stopper 91 is formed such that the passage closing member 135 is
prevented from falling out of the closing member slide portion
36c.
The passage closing member 135 is arranged around the closing
member slide portion 36c. The passage closing member 135 has
contact with the closing member slide portion 36c and moves
slidably along the closing member slide portion 36c. Further, the
passage closing member 135 is biased by a valve spring 133, which
corresponds to a "biasing member", toward the first input port 144.
One end portion of the valve spring 133 is in contact with the end
face of the cylinder 36 and the other end portion of the valve
spring 133 is in contact with the passage closing member 135.
In the first example embodiment, the thermo-valve 30 also has a
passage closing member 136, which corresponds to "second closing
means". The thermo-valve case 31 has a contact portion 31a that is
arranged to face the passage closing member 136. The contact
portion 31a protrudes from the sidewall of the inner space 32 in
the thermo-valve case 31 toward the inside of the inner space
32.
The cylinder 36 is biased by a return spring 132, which is another
biasing member, toward a direction opposite to the direction
indicated by the arrow X in FIG. 1 in which the shaft 121 is pushed
inward. The passage closing member 136 is biased by the return
spring 132 toward the contact portion 31a. Incidentally, A spring
engaging member 137 is provided in the inner space 32 of the
thermo-valve case 31. The spring engaging member 137 is formed to
establish the position of the return spring 132 on one side.
Further, the spring engaging member 137 is fixed, and therefore
does not move while the cylinder 36 is moving. The cylinder 36
includes an engaging member slide portion 36b. The spring engaging
member 137 slides on the surface of the engaging member slide
portion 36b.
The shaft 121 further includes a pushing shaft 37 for pushing the
thermo-element shaft 34. In the first example embodiment, the
thermo-element shaft 34 and the pushing shaft 37 are joined
together and thus move together.
The lid body 33 has a protruding portion 38 that protrudes toward
an outer direction of the lid body 33 opposite to the direction
indicated by the arrow X in FIG. 1. Also, the lid body 33 has a
through hole 33a. The pushing shaft 37 is inserted into the through
hole 33a. The shaft 121 passes through the through hole 33a of the
lid body 33, and a portion of the shaft 121 is exposed to the
outside. The shaft 121 is supported by the lid body 33 such that
the shaft 121 may move back and forward along the directions
indicated by the arrow 111. Further, the thermo-valve 30 has
another gasket 138 (e.g., O-ring). The gasket 138 is arranged so as
to prevent the hydraulic oil from leaking out between the pushing
shaft 37 and the through hole 33a.
The pushing shaft 37 has a flat end face 37a. An insert hole 38a is
formed in the protruding portion 38 of the lid body 33. In the
first example embodiment, a plurality of the insert holes 38a is
provided. A pin 139 having an elongated shape, which will be
described later, may be inserted into the insert holes 38a.
FIG. 2 is a side view showing the thermo-valve 30 of the first
example embodiment as viewed from the direction indicated by the
arrow X in FIG. 1. Referring to FIG. 2, a side face of the lid body
33 is formed to be circular, and a side face of the protruding
portion 38 of the lid body 33 is formed to be hexagonal. Here, the
shape of the protruding portion 38 is not limited to a hexagonal
shape. Each of the insert holes 38a is formed to extend in a
different direction from the adjacent insert hole 38a, and to reach
the through hole 33a into which the shaft 121 is inserted.
Referring to FIG. 1 and FIG. 2, the pushing shaft 37 is formed such
that the pin 139 that is inserted into the insert holes 38a, which
will be described later, contacts the end face 37a of the pushing
shaft 37 when the passage closing member 135 is in contact with the
opening portion of the first input port 144 by pushing the pushing
shaft 37 inward.
FIG. 1 shows the state that the temperature of the hydraulic oil
introduced from the first input port 144 is low. The passage
closing member 136 is in contact with the contact portion 31a by
the elastic force of the return spring 132. The end portion of the
pushing shaft 37 having the end face 37a protrudes from the
protruding portion 38 and thus is exposed to the outside. The
passage closing member 136 is in contact with the contact portion
31a, and thus the second input port 142 is under a closed state.
That is, the flow channel of the hydraulic oil 12 introduced from
the second input port 142 is interrupted. On the other hand, the
first input port 144 and the first out port 143 are under an open
state.
A hydraulic oil 11 introduced from the first input port 144 flows
into the inner space 32 as indicated by the arrow 101. Then, the
hydraulic oil that is flowed into the inner space 32 flows out of
the first out port 143 as indicated by the arrow 102. Because the
temperature of the hydraulic oil 11 is low, the temperature of the
wax 131 in the cylinder 36 is also low, and thus remains
unexpanded.
FIG. 3 is a block diagram showing a drive system 1 in the first
example embodiment when the temperature of the hydraulic oil is
low. The drive system 1 in the first example embodiment has an
engine 20 that generates drive power, and an automatic transmission
10 that receives the driver power from the engine 20 and converts
the revolutions and the rotational torques of the engine 20. The
engine 20 is a drive power source and may be either a gasoline
engine or a diesel engine. Further, the engine 20 may be an
external combustion engine, rather than an internal combustion
engine. Furthermore, the engine 20 may be configured by a
motor-generator.
The torque output from the engine 20 is converted at the automatic
transmission 10. The automatic transmission 10 may be constituted
by a torque converter and planetary gearsets. Alternatively, the
automatic transmission 10 may be a continuously variable
transmission. Also, the automatic transmission 10 may be
constituted such that a plurality of constant-meshed gears or
selective-sliding gears is provided and the engagement among the
gears changes automatically.
The engine 20 is cooled by coolant (e.g., long-life coolant). The
engine 20, a radiator 80, a thermostat 70, a water pump 60, a
heater core 90, and the first heat exchanger 40 are connected via
coolant passages 161 to 167 in which the coolant circulates.
The water pump 60 is attached to the engine 20. The thermostat 70
and the radiator 80 are provided upstream of the water pump 60. The
thermostat 70 adjusts the amount of coolant to be supplied to the
radiator 80 in accordance with the coolant temperature. The
radiator 80 radiates the heat of the coolant to the ambient
air.
The coolant from the water pump 60 is introduced into the lower
portion of the engine 20. Then the coolant is divided into two flow
channels from the upper portion of the engine 20, and the coolant
is discharged out of the engine 20. In one flow channel, the
coolant flows into the radiator 80 through the coolant passage 161.
Then, the coolant flows from the radiator 80 into the thermostat 70
via the coolant passage 163. The coolant out of the thermostat 70
returns to the water pump 60 via the coolant passage 164.
Meanwhile, a portion of the coolant passes through the coolant
passage 162, which branches from the coolant passage 161, flows
directly into the thermostat 70 bypassing the radiator 80.
In the other flow channel, the coolant that is discharged from the
engine 20 flows into the heater core 90 via the coolant passage
166. At the heater core 90, the heat of the coolant is radiated
into the vehicle compartment, thus warming the vehicle compartment.
Then, the coolant out of heater core 90 flows into the first heat
exchanger 40 via the coolant passage 167. At the first heat
exchanger 40, heat exchange is performed between the coolant and
the hydraulic oil. Then, the coolant returns to the water pump 60
via the coolant passage 165.
An automatic transmission fluid (ATF) for lubricating the
respective parts and components in the automatic transmission 10
and for transmitting the driver power flows inside the automatic
transmission 10. The hydraulic oil that flows through the
thermo-valve 30 in the first example embodiment is the automatic
transmission fluid for the automatic transmission 10. The automatic
transmission 10 is connected to the first heat exchanger 40 via an
oil passage 141.
The thermo-valve 30 is connected to the automatic transmission 10.
The thermo-valve 30 switches the flow channel of the hydraulic oil
from one to the other. The thermo-valve case 31 is attached to the
outside of the automatic transmission 10.
The thermo-valve 30 is also connected to the first heat exchanger
40. Further, the first heat exchanger 40 is connected to the heater
core 90 via a coolant passage 167. The first heat exchanger 40
performs heat exchange between the coolant flowing from the heater
core 90 and the hydraulic oil for the automatic transmission 10.
The thermo-valve 30 in the first example embodiment is arranged
between the automatic transmission 10 and the first heat exchanger
40.
The hydraulic oil outlet of the first heat exchanger 40 is
connected to an oil passage 151 via the second output port 146
formed in the thermo-valve case 31. The oil passage 151 is
connected to the second heat exchanger 50. The second heat
exchanger 50 cools the hydraulic oil by means of air-cooling. The
hydraulic oil outlet of the second heat exchanger 50 is connected
to the oil passage 152. The oil passage 152 is connected to the
second input port 142 of the thermo-valve 30.
That is, referring to FIG. 1 and FIG. 3, the first input port 144
of the thermo-valve 30 is connected to the first heat exchanger 40.
The second input port 142 of the thermo-valve 30 is connected to
the oil passage 152. The first out port 143 of the thermo-valve 30
is connected to the automatic transmission 10.
The hydraulic oil flowing inside the automatic transmission 10
discharges out of the automatic transmission 10, and flows into the
first heat exchanger 40 via the oil passage 141 as indicated by the
arrow 103. Then, after the heat exchange is performed between the
hydraulic oil and the coolant at the first heat exchanger 40, the
cooled hydraulic oil enters the thermo-valve 30 via the first input
port 144 as indicated by the arrow 101.
Thus, the cooled hydraulic oil after passing through the first heat
exchanger 40 enters the thermo-valve 30, and returns to the
automatic transmission 10 via the thermo-valve 30 without passing
through the second heat exchanger 50. Namely, when the temperature
of the hydraulic oil is low, the second input port 142 of the
thermo-valve 30 remains closed, and therefore the hydraulic oil is
not circulated through the oil passage 151, the oil passage 152,
and the second heat exchanger 50. That is, when the temperature of
the hydraulic oil is low, the hydraulic oil does not flow out from
the second output port 146 formed in the thermo-valve case 31.
FIG. 4 is a cross-sectional view showing the thermo-valve 30 in the
first example embodiment when the temperature of the hydraulic oil
entering the thermo-valve 30 is high. As the temperature of the
hydraulic oil 11 that directly enters the thermo-valve 30 from the
first heat exchanger 40 becomes higher, the temperature of the wax
131 increases due to the heat transferred through the cylinder 36,
and thereby the wax 131 expands accordingly.
As the wax 131 expands, the cylinder 36 moves relative to the
thermo-element shaft 34 in the direction indicated by the arrow
109. At this time, the passage closing member 135 moves toward the
first input port 144, so that the passage closing member 135 is
pressed against the sidewall of the inner space 32 by the biasing
force of the valve spring 133. In this way, the passage closing
member 135 is forced into contact with the opening portion of the
first input port 144, and the opening portion of the first input
port 144 is closed. Consequently, the hydraulic oil from the first
input port 144 is prevented from entering the thermo-valve 30. As
indicated by the arrow 104, the hydraulic oil from the first input
port 144 flows toward the second heat exchanger 50 via the second
output port 146.
The valve spring 133 absorbs excess load that is exerted to the
passage closing member 135 or to the cylinder 36 due to valve
overshooting after the first input port 144 is blocked in response
to an increase in the hydraulic oil temperature.
Meanwhile, as the cylinder 36 moves in the direction indicated by
the arrow 109, the passage closing member 136 moves away from the
contact portion 31a of the thermo-valve case 31, so that the second
input port 142 opens. As indicated by the arrow 105, the hydraulic
oil 12 enters the thermo-valve 30 via the second input port 142. As
indicated by the arrow 102, the hydraulic oil is discharged out of
the thermo-valve 30 via the first out port 143, and then enters the
automatic transmission 10.
The travel of each of the passage closing member 135 and the
passage closing member 136 changes according to the temperature of
the hydraulic oil. Thus, the flow rates of the hydraulic oil
introduced from the respective input ports may be adjusted as
needed.
FIG. 5 is a block diagram showing the drive system 1 when the
temperature of the hydraulic oil is high. Referring to FIG. 4 and
FIG. 5, when the temperature of the hydraulic oil is high, the
second input port 142 opens while the first input port 144 is
blocked.
Because the first input port 144 is blocked, the hydraulic oil from
the first heat exchanger 40 does not enter the thermo-valve 30
directly. That is, the hydraulic oil from the first heat exchanger
40 flows into the second heat exchanger 50 via the oil passage 151,
as indicated by the arrow 104. At the second heat exchanger 50, the
hydraulic oil is cooled by the ambient air, and the cooled
hydraulic oil then flows into the thermo-valve 30 via the oil
passage 152, as indicated by the arrow 105. Then, the hydraulic oil
enters the automatic transmission 10 through the thermo-valve
30.
Therefore, in the cooling system of the first example embodiment,
when the temperature of the hydraulic oil is relatively low, the
hydraulic oil flows only through the first heat exchanger 40 and
then returns to the automatic transmission 10. Conversely, when the
temperature of the hydraulic oil is relatively high, the hydraulic
oil flows through both the first heat exchanger 40 and the second
heat exchanger 50, and then returns to the automatic transmission
10.
When the temperature of the hydraulic oil is low, because the
hydraulic oil is heated promptly up to a normal operation
temperature by means of the heat of the engine coolant, the time
that it takes for the temperature of the hydraulic oil to reach a
temperature for starting controls, such as lock-up control, is
reduced. Also, the fuel economy is improved because the time
operated under the condition that the viscosity of the hydraulic
oil is low expands as the temperature of the hydraulic oil
increases. Further, when the temperature of the hydraulic oil is
high, the hydraulic oil may be cooled below an upper limit
temperature by being circulated through both of the first heat
exchanger 40 and the second heat exchanger 50.
When the temperature of the hydraulic oil is intermediate, the
thermo-valve 30 may be operated by minute strokes repeatedly. Thus,
the hydraulic oil cooled only by the first heat exchanger 40 and
the hydraulic oil cooled by both of the first heat exchanger 40 and
the second heat exchanger 50, are mixed in the thermo-valve 30 and
then discharged from the output port 143. Consequently, the
temperature of the hydraulic oil entering the automatic
transmission 10 may be maintained substantially constant, and
thereby the shift performance of the automatic transmission 10 may
remain stable.
The thermo-valve 30 of the first example embodiment is a mechanical
thermo-valve that controls flow rates of the fluid at two input
passages and one output passage. The thermo-valve 30 of the first
example embodiment switches the input flow channels by employing
the lid-shape valves. Therefore, valve sliding failures due to
eccentric load of the hydraulic valve, valve sliding failures due
to foreign substances contained in the hydraulic oil, and oil leaks
from gaps of the sliding valve, which are likely to occur in the
slide-type valve, may be reduced considerably.
Referring to FIG. 3, when filling the hydraulic oil externally into
the automatic transmission 10 and into the hydraulic circuit for
the automatic transmission 10 in the first example embodiment, the
hydraulic oil needs to fill up the automatic transmission 10, the
oil passage 141, the first heat exchanger 40, the oil passage 151,
the second heat exchanger 50, the oil passage 152, and the inside
of the thermo-valve 30.
In the first example embodiment, because the hydraulic oil
temperature is low at a room temperature, the second input port 142
of the thermo-valve 30 remains closed as described above. Thus, for
example, if the hydraulic oil is fed externally into the automatic
transmission 10, the automatic transmission 10, the first heat
exchanger 40, and the thermo-valve 30 may be filled up with the
hydraulic oil, while the oil passage 151, the second heat exchanger
50, and the oil passage 152 may be not filled up.
In this case, referring to FIG. 5, the oil passage 151, the second
heat exchanger 50, and the oil passage 152 may be filled up with
the hydraulic oil in such a manner that the hydraulic oil at a
higher temperature is fed externally into the automatic
transmission 10 in a state that the second input port 142 of the
thermo-valve 30 is opened as the temperature of the hydraulic oil
is raised. In this way, however, it takes a long time to fill up
the entire hydraulic circuit.
FIG. 6 is a cross-sectional view showing the thermo-valve 30 when
the hydraulic oil is fed into the hydraulic circuit in the first
example embodiment.
In the first example embodiment, the hydraulic oil at a lower
temperature is fed into the hydraulic circuit. When the hydraulic
oil is fed into the hydraulic circuit, the end face of the pushing
shaft 37 of the shaft 121 is pushed toward the inside of the
thermo-valve case 31 as indicated by the arrow 106 in FIG. 6. At
this time, the thermo-element shaft 34 pressurizes the wax 131
filled in the cylinder 36, via the back-up plate 43 and the gasket
35.
As the wax 131 is pressurized, the cylinder 36 moves toward the
first input port 144 as indicated by the arrow 110, and stops at a
predetermined position where the cylinder 36 reaches when the
temperature of the hydraulic oil flowing into the thermo-valve 30
is high. Also, the passage closing member 135 comes into contact
with the opening portion of the first input port 144, thereby the
first input port 144 is blocked. On the other hand, the passage
closing member 136 that has blocked the second input port 142,
moves away from the contact portion 31a of the thermo-valve case
31, thereby the second input port 142 is opened. As the first heat
exchanger 40 is communicated with the second heat exchanger 50, the
hydraulic circuit may be configured by the first heat exchanger 40,
the second heat exchanger 50, and the thermo-valve 30 in sequence.
Here, the direction indicated by the arrows 106, 110 may be
regarded as one example of "predetermined direction" in the
invention.
When the pushing shaft 37 is pushed inward as described above, the
end face 37a of the pushing shaft 37 is seated beyond the insert
holes 38a of the protruding portion 38. Then, for example, the pin
139 having an elongated shape as an external member, is inserted
into one of the insert holes 38a. At this time, the cylinder 36 and
the shaft 121 is biased toward the outside of the lid body 33
(i.e., the direction opposite to the arrow 106) due to the elastic
force of the return spring 132. Therefore, the end face 37a of the
pushing shaft 37 comes into contact with the inserted pin 139.
Consequently, the positions of the cylinder 36 and the shaft 121
may be anchored by inserting the pin 139. That is, the cylinder 36
may be fixed by inserting the pin 139.
FIG. 7 is a side view of the thermo-valve 30 of the first example
embodiment as viewed from the direction indicated by the arrow 106
in FIG. 6. Referring to FIG. 7, the pin 139 is inserted into one of
the insert holes 38a along the direction indicated by the arrow 107
after pushing the pushing shaft 37 inward the thermo-valve 30 such
that the end face 37a is seated beyond the insert holes 38a. The
pin 139 penetrates the protruding portion 38. Thus, the pushing
shaft 37 is prevented from falling out of the lid body 33 due to
the pin 139 penetrating the protruding portion 38.
According to the first example embodiment, a plurality of the
insert holes 38a are formed in the protruding portion 38 of the lid
body 33. Each of the insert holes 38a is formed to extend in the
different direction from the adjacent insert hole 38a. Thus, the
pin 139 may be inserted from various angles, and thereby the
working property may be improved.
By feeding the hydraulic oil into the hydraulic circuit after
fixing the shaft 121 by the pin 139, the entire hydraulic circuit
in addition to the second heat exchanger 50 may be filled up with
the hydraulic oil. For example, by feeding the hydraulic oil at a
low temperature into the automatic transmission 10, the automatic
transmission 10 and the cooling system of the automatic
transmission 10 may be filled up with the hydraulic oil.
According to the first example embodiment, the entire hydraulic
circuit may be filled up with the hydraulic oil even when the
temperature of the hydraulic oil is low. Thus, the feeding of the
hydraulic oil may be performed simply and in a shorter time.
Further, the thermo-valve 30 of the first example embodiment
provides the aforementioned advantages also when changing the
hydraulic oil of the automatic transmission 10. For example, when
discharging the hydraulic oil from the automatic transmission 10
during an oil change, or when feeding the hydraulic oil into the
automatic transmission 10 during an oil change, the hydraulic oil
may also be discharged from or fed into the automatic transmission
10 simply and in a shorter time.
In the first example embodiment, the return spring 132 for biasing
the cylinder 36 and the shaft 121 toward the outside of the lid
body 33 is provided, and the shaft 121 is fixed by the pin 139 that
is inserted into one of the insert holes 38a formed in the
protruding portion 38 to be in contact with the end face of the
shaft 121. Thus, the position of the shaft 121 may be easily
anchored. Also, because the cylinder 36 as the valve body is
anchored using the removable pin 139, it is possible to anchor the
valve body to the predetermined position or release the valve body
without difficulty.
Meanwhile, referring to FIG. 6, after feeding the hydraulic oil
into the entire hydraulic circuit, the pin 139 is pulled out. The
cylinder 36 returns to the position where the cylinder is seated
when the temperature of the hydraulic oil is low, as shown in FIG.
1, due to the elastic force of the return spring 132 as the biasing
member, and thereafter the normal valve operation resumes.
In the first example embodiment, the hydraulic oil is fed into the
hydraulic circuit after forcing the cylinder 36 to move to the
predetermined position where the cylinder 36 reaches when the
temperature of the hydraulic oil flowing into the thermo-valve 30
is high. Alternatively, the hydraulic oil may be fed into the
hydraulic circuit in the following procedure: i) a portion of the
hydraulic oil is first fed into the hydraulic circuit in a state
that the cylinder 36 is seated when the temperature of the
hydraulic oil is low, and then ii) the rest of the hydraulic oil is
fed into the hydraulic circuit in a state that the cylinder 36 is
forced to move to the predetermined position.
Further, in the first example embodiment, the hydraulic oil is fed
into the hydraulic circuit in a state that the first input port 144
connected to the first heat exchanger 40, is blocked.
Alternatively, the hydraulic oil may be fed into the hydraulic
circuit in a state that the cylinder 36 is forced to hold at a
middle position. That is, the hydraulic oil may be fed into the
hydraulic circuit in a state that the first input port 144 and the
second input port 142 are semiopen.
Further, in the first example embodiment, the shaft 121 is fixed by
means of the pin 139. Alternatively, other forms and structures may
be employed as long as the cylinder 36 as the valve body stops at
the predetermined position.
In the first example embodiment, the shaft 121 includes the
thermo-element shaft 34 and the pushing shaft 37. Furthermore, the
thermo-element shaft 34 and the pushing shaft 37 are different
members and joined together. Alternatively, the thermo-element
shaft 34 and the pushing shaft 37 may be a single member.
In the first example embodiment, the invention is applied to the
hydraulic circuit for the automatic transmission. However, the
invention may be applied to a thermo-valve in a circuit for other
fluid. For example, the invention may be applied to a heat
exchanger for cooling an engine of a motor vehicle by means of a
coolant.
Next, a thermo-valve according to the second example embodiment of
the invention will be described with reference to FIG. 8 to FIG.
11. As in the first example embodiment, a thermo-valve 29 of the
second example embodiment is arranged in a hydraulic circuit for an
automatic transmission of a motor vehicle. The thermo-valve 29 of
the second example embodiment differs from the thermo-valve 30 of
the first example embodiment in the shaft fixing structure.
FIG. 8 is a cross-sectional view showing the thermo-valve 29 of the
second example embodiment when the temperature of the hydraulic oil
is low. A case of the thermo-valve 29 in the second example
embodiment has a thermo-valve case 42 and a lid body 41.
The thermo-valve 29 has a shaft 122. The shaft 122 includes the
thermo-element shaft 34 and a pushing shaft 39. The thermo-element
shaft 34 and the pushing shaft 39 are joined together in the second
example embodiment.
The lid body 41 has a concave portion 41a. The concave portion 41a
is formed such that a portion of the push shaft 39 is exposed to
the outside. The sidewall of the concave portion 41a is threaded. A
screw member 140 as a removable member, may be screwed into the
contact portion 31a.
When the temperature of the hydraulic oil is low, the second input
port 142 is blocked because the passage closing member 136 is in
contact with a contact portion 42a. On the other hand, the first
input port 144 is open because the passage closing member 135 is
away from the opening portion of the first input port 144.
FIG. 9 is a side view showing the thermo-valve 29 of the second
example embodiment as viewed from the direction indicated by the
arrow 108 in FIG. 8. A side face of the lid body 41 is formed to be
substantial circular, and a side face of the concave portion 41a is
formed also to be substantial circular. The push shaft 39 is
arranged substantially at the center of the concave portion
41a.
FIG. 10 is a cross-sectional view showing the thermo-valve 29 when
the temperature of the hydraulic oil is high. As the temperature of
the hydraulic oil becomes higher, the wax 131 in the cylinder 36
expands accordingly. As the wax 131 expands, the cylinder 36 moves
toward the first input port 144, and thereby the passage closing
member 135 comes to block the opening portion of the first input
port 144. On the other hand, the passage closing member 136 moves
away from the contact portion 12a of the thermo-valve case 42, and
thereby the opening portion of the second input port 142 opens.
During this time, the shaft 122 does not move, but the cylinder 36
moves relative to the shaft 122.
FIG. 11 is a cross-sectional view showing the thermo-valve 29 of
the second example embodiment when feeding the hydraulic oil into
the hydraulic circuit including the thermo-valve 29.
When feeding the hydraulic oil into the hydraulic circuit, the
screw member 140 is screwed into the concave portion 41a of the lid
body 41. As the screw member 140 is screwed into the concave
portion 41a, the shaft 122 moves as indicated by the arrow 108.
That is, the shaft 122 is pushed toward the inside of the
thermo-valve case 42. Due to movement of the shaft 122, the wax 131
in the cylinder 36 is pressurized via the gasket 35, and thereby
the cylinder 36 moves toward the first input port 144 as indicated
by the arrow 110.
Then, the passage closing member 135 blocks the opening portion of
the first input port 144. At this time, on the other hand, the
passage closing member 136 moves away from the contact portion 42a
of the thermo-valve case 42, and thereby the second input port 142
opens. Therefore, when feeding the hydraulic oil into the hydraulic
circuit, the cylinder 36 is forced to move to the predetermined
position where the cylinder 36 reaches when the temperature of the
hydraulic oil flowing into the thermo-valve 30 is high even though
the temperature of the hydraulic oil is still low. In the first and
second example embodiments, the first input port 144 may be
regarded as one example of "first input passage" in the invention,
and the second input port 142 may be regarded as one example of
"second input passage" in the invention.
In the second example embodiment, when feeding the hydraulic oil
into the hydraulic circuit, the valve body may be forced to move to
the predetermined position even though the temperature of the
hydraulic oil is still low, and therefore the oil passages that are
normally open at a higher temperature may also be filled up with
the hydraulic oil.
In the second example embodiment, the concave portion 41a is
provided, and the shaft 122 is pushed inward by means of the screw
member 140 that is screwed into the concave portion 41a. Thus, the
cylinder 36 may be moved to the predetermined position without
difficulty. Also, the position of the shaft 122 may be finely
adjusted by means of the screw member 140 when feeding the
hydraulic oil into the hydraulic circuit.
Other structures, effects and advantages in the second example
embodiment are similar to those in the first example embodiment,
and therefore they are not described here again.
In the respective drawings, like elements and components are
denoted by like numerals.
While the invention has been described with reference to example
embodiments thereof, it is to be understood that the invention is
not limited to the described embodiments or constructions. To the
contrary, the invention is intended to cover various modifications
and equivalent arrangements. In addition, while the various
elements of the example embodiments are shown in various
combinations and configurations, other combinations and
configurations, including more, less or only a single element, are
also within the spirit and scope of the invention.
* * * * *